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4 2 Sheets-Sheet 1. I'. C. HOLMES. GRANK SHAFT.

Patented July-28, 1896.

(No Model.)

' 2 sums-sheet z.

F. C. HOLMES. GRANK SHAFT.'

Patented July Nix 11W N UNiTnn Sterns ffnfrsnr @risica FRANK c. nomine,or 'scanne-on `resinsvia-fanLA., -fissicnoa' er ninnc'r AND Massinaesinet-rends, Torun. incitatif/inns' iviisnt consi-infr,

OF PENNSYLVANIA.

f ceANKfss'Arn SPECIFICATION forming partv of Letters Patent No.564,958, dated July 2S, i896. Application filed Octobei' 31, 1895.Serial No. 567,492. (No model.)

To @ZZ whom it mag/,coleccion i l Be it knovrn that I, FRANK C.llOLMEs., of Scranton, in the county of llackawanuaA and State ofPennsylvania, have invented certain new and Vuseful Improvements inCrank- Shafts; and I do 'hereby declare that the following is a full,clean, and exact description thereof,`reference being had totheaccompanying drawings, andto the letters of reference Io' markedthereon, which form part of this speci ication. f

This invention is an improvement inthe crank-shafts and in theconnections of the cranks to the shats'in bicycles, die.; and itconsists in the novel construction and-coml bination of partshereinafter claimed, the bestform of the invention now known to mebeinghereinafter described, and-shown in the accompanying drawings, inwhich- Figure l is a centrallongi-tudinal section through the barrel ofa bicycle-frame, showing the crankshaft and cranks in full lines.- Ei g.2 is a ongitudinal vertical section through Fig. l. Fig. 3 is a detailend or side View of the sprocket-crank; Fig. 4C, a transverse section online e 4, Fig. 3, Fig. 5 isa detail section similar to Fig.' 2, showinga modified form of the-invention.` Fig. 6 is a detail.

*Referring* to the accompanying drawings by letters, A designates thebarrel portion of the frame ofa bicycle iof any suitable construction. Asleeve B is supported and centered Within the barrel byball-bearings C,as shown in the drawingsg or in any other 3 5 desired manner: y The endsbof sleeve B projeet beyond the ends ofv the barrel and are threadedexteriorly, as shown, the threads on opposite ends being respectivelyright and left hand.

`Through sleeve B and fitted closely therein, so astohavc the leastpossible lateral play, is the crank-shaft D, which is preferably formedof one piece and projects at' both ends slightly beyond the ends of thesleeve. The ends of the crank-shaft are preferably tapered 4on oppositesides, as at d, to tit into correspondingly tapered sockets e in theshown in Figs. l and 2.

`then removed, and the cranks will be found 7o bosses of thepedal-cranks E, and these ilat-v tlsggeditapered sockets vge clearthrough to the i,

milliitrces oi? the cra :iks and the ends of j the shaft come ilush withthe outside faces,

in this way permitting a perfect and strong fit to be'made .between the'differentV parts. The hubs ofthe cranks are large and extend backwardfrom sockets c', which are threaded 5 5 to 'lit over the threaded endsof 'the sleeve l5,

as shown.

In assembling the parts sleeve l is first centered and supported in thebarrel on suitable bcarings, and is locked by means of the 6o ordinarykey Z. (Shown in Fig. 2. Shaft D is then peti-nto the `sleeve-and thecranks are slipped on the ends of the shaft and simultaneously turned insanie direction, so as to screnr upon the ends oi sleeve l5, the cranksbeing thus drawn toward each other bythc screwthrcads until the taperedends of the shaft it into the sockets e of the cranks, as Thelocking-key is to be iirmly'mounted on and fastened to the shaft D, thesleeve B serving both to 'unite the cranks and to ybind `them on theends of the crank-shaft.

It'will be observed that all side or literal 7 5 strain which might beexerted on the threaded ends of the sleeve if the shaft Was removed isobviated by the close iitting between the cranks and crank-shaft andcrank-shaft and sleeve.

One of the most important features of the invention is the fact that thecranks are directly fastened to'. the shaft and that the strain from onecrank to the other is exerted through a solid shaft and not upon thethreads or sleeve, and that there is oniy one long sleeve between thetwo cranks, which draws the cranks together, and the sockets are sostrongly constructed that they cannot be easily injured by a fall of theWheel. 9o

The sleeve drawing the cranks upon then tapered ends of the vcrank-shaft'makes the joints so. close that there is no play of the, cranks uponthe shaft or in relation to eachI other, and so long as the sleeve isfree to revolve in the barrel it will be impossible for the cranks toloosen or turn off, for the cranks are engagedV by oppositely-leadingscrew-threads, and being firmly united to the crank-shaft the taperedsockets they cannot be turned i131.

" tion is to secure the cranks on the crankshaft ueeiwieetly of nachother unless the sleeve ne tricked. l do not, however, limit myself tothe use of in pered ends on crank-shaft and tapered soci-:ets in thefrank-bosses. They are easy to-droi-i-forge, butt-he essential featureis to 'prevent rotation of the cranks on the shaft.`

The employment of' a solid shaft, though not essential, is obvionsly agreat advantage inpoint of strength and economy of construction, and allthe parts are such that they can be easily drop-forged by ordinarytools, and can be assembled Without special tools.

The construction described is simple, very stron g, durable, andeconomical, and the parts so constructed, when properly assembled,appear and are as stiff asA if made of a single piece of metal. l

As shown, cnc of the cranksis forged `with arms E radiating from itsboss, to which a sprocket-wheel rini F can be attached.

In Fig. 5 I have illustrated a modification Y of the construction shownin Fig. l, by making the shaft integral with or Welded to one of thecranks. The other parts and connec` tions remain the saine, however.

I do notliinit'inyself to the precise construction herein shown and'described, as Various modifications may be made therein While retainingall the essential features of myinvention. l v

v One of the principal features of the inyen-` by means of an internalbond, doing away with pins and keys between the cranks .and crank-shaftand yet putting all the strain of rotation of cranks directly upon thecrankf shaft.

llaving thus described my invention, what 4o I therefore claim as new,and desire to secure 'by Letters 'Patent thereon, is-

l.. In a bicycle the ccnihination of a crank and crank-shaft, saidcrank-shaft having a V lthe crank-shaft, so that the end of shaft comesiinsh with face of crank, With a long sleeve closely fitted to andsurrounding the crankshaft and having oppositely-screw-threaded endsfitted into sockets on back. of the cranks whereby the cranks are firmlyheld onthe crank-shaft, all substantially as and for the purposedescribed.

2. In a bicycle, the combination of the crankshaft havingangular ends,and the detachable crankshaying sockets in their bosses fitting the endsof the shaft; Witha sleeve fitted on the shari; and havingoppositelythreaded ends cn gag-in g correspondingtlneaded enlargementsof the sockets inthe bosses of the' cranks, whereby the cranks aredrawn. toward each other and bound on the shaft, all substantially asand for the purpose described.

The combination ,of the barrel, the rotatablel sleeve mounted therein,projecting be yond the ends thereof and oppositely threaded on itsprojecting ends and the shaft fitted in the sleeve and projecting beyondthe ends thereof; with the ,cranks tted onthe ends of the shaft butnotfrotatable thereon; having internally-threaded sockets in theirbosses .engaging .theends of the-sleeve whereby the cranks are boundtogether an d upon the shaft,

'suiestantiallyy as described.

In testimony that I claim the foregoing as nyoWnI ax my signature inpresence of two witnesses.

. FRANK (i. HOLMES. Vtitnesses: JAMns-R. MANSFIELD,

T. H. ALEXANDER.

